html, body, .main{
    height: 100%;
    font-size: 14px;
    overflow: hidden;
    margin: 0;
    padding: 0;
    color: #333;
}

*{
    box-sizing: border-box;
}

input{ margin: 0; }

input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* Firefox */
input[type=number] {
    -moz-appearance: textfield;
}

input[type=text],
input[type=number] {
    border: none;
    border-bottom: 2px solid #d4d4d4;
    outline: none;
    transition: border-color .2s;
    padding: 4px;
    font-weight: bold;
    color: #0086f6;
    background-color: transparent;
}

input[type=text]:focus,
input[type=number]:focus {
    border-color: #0086f6;
}

button{
    border: none;
    color: white;
    background-color: #0086f6;
    border-radius: 4px;
    padding: 6px 12px;
    font-size: 14px;
    transition: background-color .2s;
    text-transform: uppercase;
}

button:hover{
    cursor: pointer;
    background-color: #0075d4;
}

button:active{
    background-color: #0086f6;
}

button.disabled{
    cursor: not-allowed;
    background-color: #d4d4d4;
}
.flex1{ flex: 1 }
.m10{ margin: 10px; }
.mx10{ margin: 0 10px; }
.mt10{ margin-top: 10px; }
.mr10{ margin-right: 10px; }
.ml10{ margin-left: 10px; }
.mb10{ margin-bottom: 10px; }
.mr20{ margin-right: 20px; }
.highlight{
    font-size: 24px;
    font-weight: bold;
}
.highlight.bigger{
    font-size: 30px;
    color: #00b87a;
}
.highlight.green{
    color: #00b87a;
}
.highlight.orange{
    color: #ff7700;
}
.highlight.gray{
    color: #999;
}

.wrapper{
    display: flex;
    flex-direction: column;
    height: 100%;
    padding: 20px 10px;
    overflow: hidden;
}

.inline{
    display: flex;
    align-items: center;
}

.wrap{
    flex-wrap: wrap;
}

.operators{
    display: flex;
    align-items: center;
    margin-right: 10px;
    margin-bottom: 10px;
}

.operators .operator{
    display: flex;
    align-items: center;
    margin-right: 10px;
}

.operators .operator input{
    margin-right: 4px;
}

.list{
    flex: 1;
    overflow: overlay;
    display: flex;
    flex-wrap: wrap;
    padding: 12px 0;
    margin-top: 10px;
    align-items: flex-start;
    align-content: flex-start;
    justify-content: flex-start;
    border-top: 1px solid #f4f4f4;
}

.item{
    padding: 8px 12px;
    margin-right: 5px;
    margin-bottom: 5px;
    display: flex;
    align-items: center;
    background-color: #f4f4f4;
    transition: background-color .2s;
}

.item.UNDO{
    background-color: #f4f4f4;
}
.item.CORRECT,
.item.CORRECT input{
    color: #fff;
    background-color: #00b87a;
}
.item.MISTAKE,
.item.MISTAKE input{
    color: #fff;
    background-color: #f63b21;
}


.item .question {
    display: flex;
    align-items: center;

}

.item .question span {
    width: 24px;
    text-align: center;
}

.item input {
    width: 40px;
}

.progress{
    flex: 1;
    height: 10px;
    min-width: 100px;
    border-radius: 8px;
    background-color: #efefef;
}

.progress .highlight {
    height: 10px;
    border-radius: 8px;
    background-color: #0086f6;
    transition: width .2s;
}

.drawer {
    position: fixed;
    display: flex;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    overflow: hidden;
    z-index: 9;
}

.drawer.left { justify-content: flex-start; }
.drawer.right { justify-content: flex-end; }

.drawer .mask{
    position: absolute;
    z-index: 1;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, .6);
}

.drawer .main{
    position: relative;
    z-index: 2;
    background-color: #fff;
    padding: 20px;
    display: flex;
    flex-direction: column;
    max-height: 100%;
    overflow: hidden;
}

.drawer .header {
    flex-shrink: 0;
    font-weight: bold;
    padding-bottom: 12px;
    border-bottom: 1px solid #e4e4e4;
}

.drawer .body {
    flex: 1;
    overflow: overlay;
}

.history-item{
    font-size: 12px;
    padding: 4px;
}

.history-item:hover{
    background-color: #f4f4f4;
}